This invention relates to electrical assemblies.
The invention is more particularly concerned with electrical assemblies of the kind including a surface mount capacitor.
Surface mount capacitors are increasingly used in electrical assemblies, such as in those for filtering electromagnetic interference. The most commonly used capacitors are of rectangular shape having a metal pad at each end extending across the width of the capacitor. The pads on the capacitor are aligned with, and soldered to, respective pads on the substrate or circuit board, which in turn are connected to, or formed as a part of, respective tracks on the substrate. This arrangement can perform satisfactorily over a limited range of frequencies but at higher frequencies, typically above about 80 MHz, the performance of the capacitor is degraded as a result of parasitic inductance between the capacitor and the tracks connected to it. The effect of this can be reduced by using special capacitors but these often require more space or are expensive. Where many different lines have to be filtered with their own capacitors, it can add significantly to the cost and volume of the complete assembly and make maintenance more difficult.